Re: GDB/MI reporting non-ASCII file names

[Eli Zaretskii <eliz@gnu.org>]

> Date: Wed, 30 Sep 2015 15:49:42 +0100
> From: Pedro Alves <palves@redhat.com>
> CC: gdb@sourceware.org
> 
> >>  https://sourceware.org/ml/gdb/2010-08/msg00129.html
> > 
> > Thanks.  So it's hard-wired in MI, and the grammar requires that.  Too
> > bad.
> 
> We can always extend it.  Maybe we just need to document that ascii is
> the default, and that frontends should
> issue -gdb-set print sevenbit-strings off if they want non-ascii?
> Seems like Eclipse ended up doing that.

But "-gdb-set print sevenbit-strings off" doesn't seem to work: I get
spurious "\200" strings which disrupt the whole sequence.  I thought
that was because 7-bit strings were a requirement in MI, for some
reason.

But now I think the culprit is this part of printchar:

  if (c < 0x20 ||
      (c >= 0x7F && c < 0xA0) ||       <<<<<<<<<<<<<<<<<<<<<<<<<<<<<
      (sevenbit_strings && c >= 0x80))

This produces octal escapes for characters in 0x7F..0x8F regardless of
the value of sevenbit_strings, which does the wrong thing with
non-leading bytes of UTF-8 sequences.

If you compile a program from a source file whose name includes
non-ASCII characters, then debug that program with -i=mi, do you see
the file names correctly, after turning 7 bits off?

Btw, I see valid non-ASCII file names when I use CLI and the
annotations instead.  So does this mean we don't use printchar for
emitting file names in that case?